Collecting feedback is a job for the marketing research department, not customer service.

Customer service teams collaborate closely with marketing teams on feedback collection and analysis. After all, customer service channels are ideal for collecting feedback, and CSRs (customer service representatives) offer a more pleasing customer experience by collecting feedback while handling complaints. The customer service team should use every interaction as an opportunity to collect quantitative and qualitative feedback on customers' real experiences with the company. By informing an angry customer you're taking their feedback seriously, they usually start to calm down instantly.